JP2014219100A - Wheel bearing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a wheel bearing device having improved reliability in detecting a rotating speed by enhancing the airtightness of a fitting part between a protecting cover and an outward member to protect a magnetic encoder, and enhancing the rigidity of the protecting cover to suppress the deformation.SOLUTION: A protecting cover 10 includes a fitting part 10a to be pressed into an end inner peripheral face 2d of an outward member 2, a shield part 10c extending radially inward from the fitting part 10a via a diameter-shrunk part 10b having a stepped shape until a rotating speed sensor comes close to or abuts on the side face, and a bottom part 10e for blocking the end of an inward member 1 from the shield part 10c via a stepped part 10d. A seal member 15 is integrally joined to the outer periphery of the diameter-shrunk part 10b. The seal member 15 includes an annular part 15b formed with its diameter somewhat smaller than the outer diameter of the fitting part 10a, and a protruded part 15a formed with its diameter somewhat larger than the outer diameter of the fitting part 10a. The protruded part 15a is pressed into an end inner peripheral face 2d of the outward member 2 via a predetermined interference.

Description

  The present invention relates to a wheel bearing device equipped with a protective cover for rotatably supporting a wheel of an automobile or the like and sealing the inside of the bearing.

  There is provided a wheel bearing device in which a rotation speed detection device for detecting a rotation speed of a vehicle and controlling an anti-lock brake system (ABS) is incorporated in the bearing while rotatably supporting a vehicle wheel with respect to a suspension device. Generally known. Conventionally, in such a wheel bearing device, a sealing device is provided between an inner member and an outer member that are in rolling contact with a rolling element, and a magnetic encoder in which magnetic poles are alternately arranged in a circumferential direction is provided as the sealing device. It is integrated with. A rotational speed sensor that is arranged facing this magnetic encoder and detects a change in magnetic pole of the magnetic encoder accompanying the rotation of the wheel is mounted on the knuckle after the wheel bearing device is mounted on the knuckle constituting the suspension device. .

  As an example of such a wheel bearing device, a structure as shown in FIG. 7 is known. The wheel bearing device includes an outer member 50, an inner member 51, and a plurality of balls 52 accommodated between the outer member 50 and the inner member 51. The inner member 51 includes a hub ring 53 and an inner ring 54 press-fitted into the hub ring 53.

  The outer member 50 integrally has a vehicle body mounting flange 50b fixed to the knuckle 65 constituting the suspension device on the outer periphery, and double row outer rolling surfaces 50a and 50a are integrally formed on the inner periphery. A sensor 63 is supported and fixed to the knuckle 65 by a screw 66.

  The hub wheel 53 integrally has a wheel mounting flange 55 for mounting a wheel (not shown) at one end, an inner rolling surface 53a on the outer periphery, and a small diameter step extending in the axial direction from the inner rolling surface 53a. A portion 53b is formed. The inner ring 54 has an inner rolling surface 54a formed on the outer periphery, and is fixed in the axial direction by a caulking portion 53c formed by plastically deforming an end portion of the small diameter step portion 53b.

  A seal ring 56 is fitted and fixed to the outer end portion of the outer member 50, and the lip of the seal ring 56 is in sliding contact with the base portion 55 a of the wheel mounting flange 55. On the other hand, an encoder 57 is fitted and fixed to the outer peripheral surface of the inner end portion of the inner ring 54. The encoder 57 includes a support ring 58 having an L-shaped cross section, and an annular encoder body 59 attached and supported on the side surface of the support ring 58 over the entire circumference. In the encoder body 59, magnetic poles N and S are alternately magnetized at equal intervals in the circumferential direction.

  The inner end opening of the outer member 50 is closed by the cover 60. The cover 60 is formed in a petri dish from a nonmagnetic plate material such as a non-magnetic stainless steel plate, an aluminum alloy plate, or a high-functional resin, and has a circular closing plate portion 61 and an outer peripheral edge portion of the closing plate portion 61. And a cylindrical fitting portion 62 formed in the above.

  The side surface of the encoder main body 59 that constitutes the encoder 57 is disposed in close proximity to the cover 60, and the detection unit 64 of the sensor 63 is in proximity to or in contact with the side surface of the cover 60. Are opposed to each other through a cover 60. Thereby, the presence of the cover 60 can prevent water, iron powder, magnetic fragments, etc. from entering between the sensor 63 and the encoder 57, thereby preventing the sensor 63 and the encoder 57 from being damaged. It is possible to prevent the regular and periodic magnetic property changes of the main body 59 from being disturbed or deteriorated (see, for example, Patent Document 1).

JP 2000-249138 A

  However, such conventional wheel bearing devices have the following problems. First, since the cover 60 is simply fixed to the outer member 50 by metal fitting, sufficient airtightness of the fitting portion cannot be ensured unless the surface accuracy and roughness of the fitting surface are improved.

  Further, since the shape of the cover 60 is a simple U-shaped cross section, the rigidity is insufficient, and the cover 60 may be deformed by contact with a flying stone or the like, and may come into contact with the encoder main body 59. Furthermore, since the detection unit 64 of the sensor 63 faces the encoder 57 via the cover 60, the air gap may increase and the detection accuracy may decrease.

  The present invention has been made in view of such circumstances, and improves the airtightness of the fitting portion between the protective cover and the outer member to protect the magnetic encoder, and also increases the rigidity of the protective cover to suppress deformation. And it aims at providing the bearing device for wheels which raised the reliability of rotation speed detection.

  In order to achieve such an object, the invention according to claim 1 of the present invention includes an outer member in which a double row outer rolling surface is integrally formed on the inner periphery, and a wheel attachment for attaching a wheel to one end. The hub ring has a flange integrally formed with a small diameter step portion extending in the axial direction on the outer periphery, and at least one inner ring press-fitted into the small diameter step portion of the hub ring. An inner member in which a double-row inner rolling surface facing the running surface is formed, and a double-row rolling element that is movably accommodated between the inner and outer members. And a magnetic encoder externally fitted to the inner ring, a seal is attached to the outer end of the outer member, and a protective cover is attached to the inner end of the outer member, A vehicle in which an opening of an annular space formed by the outer member and the inner member is sealed In the bearing device, the protective cover is formed in a cup shape from a non-magnetic steel plate, and is fitted into a cylindrical fitting portion that is press-fitted into the inner peripheral surface of the end portion of the outer member. The rotational speed sensor includes a disc-shaped shielding portion that extends inward in the radial direction and is close to or abuts against the inner side surface, and a seal member is integrally joined to the outer peripheral portion of the reduced diameter portion. And is press-fitted into the inner peripheral surface of the end portion of the outer member via a predetermined scissors, the inner end surface of the outer member is formed so as to protrude to the inner side from the large end surface of the inner ring, There is a gap between the large end surface and the shielding portion.

  Thus, in the inner ring rotating type wheel bearing device, the protective cover is formed in a cup shape from a non-magnetic steel plate, and is fitted into a cylindrical fitting portion that is press-fitted into the inner peripheral surface of the end portion of the outer member. The rotational speed sensor includes a disk-shaped shielding portion that extends inward in the radial direction from the fitting portion via the reduced diameter portion and is close to or in contact with the side surface on the inner side, and on the outer peripheral portion of the reduced diameter portion. The seal member is integrally joined, and is press-fitted into the inner peripheral surface of the end portion of the outer member via a predetermined squeeze, and the end surface on the inner side of the outer member is formed to protrude to the inner side from the large end surface of the inner ring. Since there is a gap between the large end surface of the inner ring and the shielding portion, the step between the inner end surface of the outer member and the large end surface of the inner ring is defined to shield the large end surface of the inner ring from the protective cover. A labyrinth seal is formed between the inner surface and the bearing. It is possible to prevent the filled grease from flowing to the inner side end of the inner member beyond the shielding portion of the protective cover, prevent poor lubrication and prolong the service life. Since there is no need to fill the inside of the bearing with excess grease, the temperature rise of the bearing due to stirring resistance can be prevented, and the sealing performance can be improved.

  Further, as in the invention described in claim 2, if the seal member has a convex portion formed to have a diameter slightly larger than the outer diameter of the fitting portion of the protective cover, over a long period of time. Thus, the airtightness of the fitting surface between the outer member and the protective cover can be enhanced. Further, as in the invention described in claim 3, the reduced diameter portion may be formed in a tapered shape.

  According to a fourth aspect of the present invention, the seal member does not protrude toward the inner side from the outer surface of the shielding portion at least in a single state before the protective cover is fitted to the outer member. If it is set in this way, it is not necessary to move the rotation speed sensor away from the magnetic encoder more than necessary in order to avoid interference with the seal member, the air gap can be set to the minimum, and detection accuracy is further improved. Can do. Note that at least the protective cover is set so as not to protrude to the inner side from the outer surface of the shielding portion in a single state before the protective cover is fitted to the outer member. It is preferable that it is set so as not to protrude to the inner side from the outer surface of the shielding portion in a state where it is fitted and fixed to (ie in use).

  Further, as in the invention according to claim 5, the fitting volume of the convex portion of the seal member is such that the annular portion of the seal member and the inner periphery of the end portion of the outer member are in a state where the press-fitting jig is in contact. If it is set to be smaller than the volume of the annular space formed between the surface and the surface, even if the convex portion of the seal member is compressed and raised when the protective cover is press-fitted, the annular portion of the seal member It can be allowed to become an escape portion, and can be prevented from protruding and being damaged from the end face of the outer member.

  Preferably, as in the invention described in claim 6, the detection surface of the magnetic encoder and the large end surface of the inner ring are substantially flush or set so as to slightly protrude toward the inner side from the large end surface. Thus, the air gap can be easily adjusted, and the air gap can be aimed at smaller.

  Further, as in the seventh aspect of the invention, if the connecting portion between the inner peripheral surface of the end portion of the outer member and the chamfered portion is formed in an arc shape having a predetermined radius of curvature, the press-fitting property of the seal member Can be improved to prevent damage and uplift during press-fitting.

  Preferably, as in the invention described in claim 8, if the inner peripheral surface of the end portion of the outer member and the chamfered portion including at least the joint portion are simultaneously ground by a general grinding wheel, the end The connecting portion between the inner peripheral surface of the part and the chamfered portion is formed smoothly, so that the press-fitting property of the seal member is further improved, and the seal member can be prevented from being damaged and raised during press-fitting.

  Further, as in the ninth aspect of the invention, if the plate air gap thickness of the shielding portion of the protective cover is formed thinner than the plate thickness of other portions, the sensor detection portion and the magnetic encoder It can be set small, and detection accuracy can be further enhanced.

  The wheel bearing device according to the present invention integrally has an outer member integrally formed with a double row outer rolling surface on the inner periphery, and a wheel mounting flange for mounting the wheel on one end, and on the outer periphery. A hub ring formed with a small-diameter step portion extending in the axial direction, and at least one inner ring press-fitted into the small-diameter step portion of the hub ring, the inner side of the double row facing the outer rolling surface of the double row on the outer periphery An inner member on which a rolling surface is formed, a double row rolling element that is slidably accommodated between the rolling surfaces of the inner member and the outer member, and the inner ring is externally fitted to the inner ring. A magnetic encoder, and a seal is attached to an outer end of the outer member, and a protective cover is attached to an inner end of the outer member, and the outer member, the inner member, In the wheel bearing device in which the opening of the annular space formed by is sealed, A protective cover is formed in a cup shape from a non-magnetic steel plate, and is fitted into a cylindrical fitting portion that is press-fitted into the inner peripheral surface of the end portion of the outer member, and a radial direction from the fitting portion via a reduced diameter portion. A disc-shaped shielding portion that extends inward and has a rotational speed sensor that approaches or abuts on the side surface on the inner side, and a seal member is integrally joined to an outer peripheral portion of the reduced diameter portion; It is press-fitted into the inner peripheral surface of the end portion of the member via a predetermined squeeze, and the inner side end surface of the outer member is formed to protrude to the inner side from the large end surface of the inner ring, and the large end surface of the inner ring and the shielding Since there is a gap between the inner ring and the inner ring, by defining a step between the inner end face of the outer member and the large end face of the inner ring, the gap between the large end face of the inner ring and the inner face of the shielding part of the protective cover A labyrinth seal is formed on the bearing and the grease filled in the bearing is protected by a protective cover. It is possible to suppress the flow to the inner side end of the inner member beyond the shielding portion of the inner member, prevent poor lubrication and prolong the service life, and preliminarily add excess grease inside the bearing. Since it is not necessary to fill, the temperature rise of the bearing due to stirring resistance can be prevented, and the sealing performance can be improved.

It is a longitudinal section showing one embodiment of a wheel bearing device concerning the present invention. (A) is the principal part enlarged view of FIG. 1, (b) is the elements on larger scale of (a). It is sectional drawing which shows the protective cover single-piece | unit based on this invention. It is sectional drawing which shows the modification of the protective cover of FIG. It is explanatory drawing which shows the processing method of an outward member. It is a principal part enlarged view which shows the modification of the protective cover of Fig.2 (a). It is a principal part enlarged view which shows the conventional wheel bearing apparatus.

  A vehicle body mounting flange to be attached to the knuckle on the outer periphery, an outer member in which a double row outer rolling surface is integrally formed on the inner periphery, and a wheel mounting flange to mount a wheel on one end A hub wheel integrally formed and having one inner rolling surface opposed to the double-row outer rolling surface on the outer periphery, and a small-diameter step portion extending in the axial direction from the inner rolling surface, and the hub wheel An inner member formed of an inner ring that is press-fitted into the small-diameter step portion and formed with the other inner rolling surface opposite to the double row outer rolling surface, and the inner member and the outer member. A caulking formed by plastically deforming an end portion of a small-diameter step portion of the hub wheel, comprising a double-row rolling element that is rotatably accommodated between the running surfaces, and a magnetic encoder that is externally fitted to the inner ring. The inner ring is in contact with the hub ring in a state where a predetermined bearing preload is applied by the portion. And a seal is attached to the outer end of the outer member, and a protective cover is attached to the inner end of the outer member so that the outer member and the inner member In the wheel bearing device in which the opening of the formed annular space is sealed, the protective cover is formed in a cup shape from a non-magnetic steel plate and is press-fitted into the inner peripheral surface of the end portion of the outer member. And a disc-shaped shielding portion that extends radially inward from the fitting portion via the reduced diameter portion, and the rotational speed sensor is close to or abutting on the side surface on the inner side, A seal member is integrally joined to the outer peripheral portion of the reduced diameter portion, and is press-fitted into the inner peripheral surface of the end portion of the outer member via a predetermined shimiro, and the inner end surface of the outer member is the inner ring surface of the inner ring. It is formed so as to protrude to the inner side from the large end surface, and the large inner ring A gap between the surface and the shielding portion, the sealing member is provided with a convex portion formed slightly larger in diameter than the outside diameter of the fitting portion of the protective cover.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
1 is a longitudinal sectional view showing an embodiment of a wheel bearing device according to the present invention, FIG. 2 (a) is an enlarged view of a main part of FIG. 1, and (b) is a partially enlarged view of (a). 3 is a cross-sectional view showing a single protective cover according to the present invention, FIG. 4 is a cross-sectional view showing a modification of the protective cover of FIG. 3, and FIG. 5 is an explanatory view showing a method for processing the outer member. In the following description, the side closer to the outer side of the vehicle when assembled to the vehicle is referred to as the outer side (left side in FIG. 1), and the side closer to the center is referred to as the inner side (right side in FIG. 1).

  This wheel bearing device is for a driven wheel referred to as a third generation, and is a double row rolling element housed in a freely rollable manner between the inner member 1, outer member 2, and both members 1,2. (Balls) 3 and 3. The inner member 1 includes a hub ring 4 and an inner ring 5 press-fitted into the hub ring 4 through a predetermined shimiro.

  The outer member 2 is made of medium and high carbon steel containing 0.40 to 0.80 wt% of carbon such as S53C, and integrally has a vehicle body mounting flange 2b for mounting to a knuckle (not shown) on the outer periphery. Double row outer rolling surfaces 2a, 2a are integrally formed. These double-row outer raceway surfaces 2a and 2a are formed with a hardened layer having a surface hardness of 58 to 64 HRC by induction hardening.

  The hub wheel 4 integrally has a wheel mounting flange 6 for mounting a wheel (not shown) at an end portion on the outer side, and hub bolts 6a are implanted at circumferentially equidistant positions of the wheel mounting flange 6. Yes. Moreover, the inner side rolling surface 4a which opposes one (outer side) of the said double row outer side rolling surface 2a, 2a and the small diameter step part 4b extended in an axial direction from this inner side rolling surface 4a are formed in outer periphery. Yes. On the other hand, the inner ring 5 is formed on the outer periphery with an inner rolling surface 5a facing the other (inner side) of the double row outer rolling surfaces 2a, 2a, and a small-diameter step portion 4b of the hub wheel 4 via a predetermined shimoshiro. It is press-fitted. The inner ring 5 is fixed in the axial direction in a state where a predetermined bearing preload is applied by a crimping portion 7 formed by plastically deforming an end portion of the small-diameter stepped portion 4b of the hub wheel 4 radially outward. .

  Between the double row outer rolling surfaces 2a, 2a of the outer member 2 and the double row inner rolling surfaces 4a, 5a facing these, the double row rolling elements 3, 3 are respectively accommodated, and the cage 8 , 8 are held so as to roll freely. A seal 9 is attached to the outer opening of the annular space formed between the outer member 2 and the inner member 1, and the magnetic encoder 14 and the protection are provided to the inner opening. A cover 10 is attached to prevent leakage of lubricating grease sealed in the bearing and prevent rainwater, dust, and the like from entering the bearing from the outside.

  In addition, although the wheel bearing apparatus comprised by the double row angular contact ball bearing which used the ball for the rolling element 3 was illustrated here, it is not restricted to this, The double row tapered roller bearing which used the tapered roller for the rolling element 3 It may consist of. In addition, here, a third generation structure in which the inner rolling surface 4a is formed directly on the outer periphery of the hub wheel 4 is illustrated, but although not shown, a pair of inner rings are press-fitted and fixed to the small-diameter step portion of the hub wheel. It may be a first generation or second generation structure.

  The hub wheel 4 is made of medium and high carbon steel containing 0.40 to 0.80 wt% of carbon such as S53C, and extends from the inner rolling surface 4a to the base 6b on the inner side of the wheel mounting flange 6 to the small diameter step 4b. The surface is hardened by induction hardening in the range of 58 to 64 HRC. In addition, the crimping part 7 is made into the surface hardness after a forge process. This facilitates the caulking process, prevents the occurrence of microcracks during the process, improves not only the wear resistance of the base part 6b serving as the seal land part of the seal 9, but also loads the wheel mounting flange 6. Therefore, the durability of the hub wheel 4 is improved. The inner ring 5 and the rolling element 3 are made of high carbon chrome bearing steel such as SUJ2, and are hardened in the range of 58 to 64 HRC to the core portion by quenching.

  The seal 9 is an integrated seal composed of a core metal 11 press-fitted into the inner periphery of the outer side end portion of the outer member 2 through a predetermined shimiro and a seal member 12 joined to the core metal 11. It is configured. The core metal 11 is formed by pressing a cold-rolled steel plate (JIS standard SPCC system or the like).

  On the other hand, the sealing member 12 is made of synthetic rubber such as nitrile rubber and is integrally joined to the core metal 11 by vulcanization adhesion. This seal member 12 is formed to be inclined outward in the radial direction, and is provided with a side lip 12a that is in sliding contact with a side surface on the inner side of the wheel mounting flange 6 with a predetermined squeeze, and a base 6b that is formed with a circular cross section. The side lip 12b is in sliding contact with the squeeze and the grease lip 12c is formed so as to be inclined inward of the bearing.

  A support ring 13 having an L-shaped cross section is fitted on the inner ring 5. The support ring 13 includes a cylindrical portion 13a that is press-fitted into the outer diameter of the inner ring 5, and a standing plate portion 13b that extends radially outward from the cylindrical portion 13a, and a magnet is formed on the inner side surface of the standing plate portion 13b. The encoder 14 is integrally joined by vulcanization adhesion. In the magnetic encoder 14, magnetic powder such as ferrite is mixed in synthetic rubber, and magnetic poles N and S are magnetized alternately at equal pitches in the circumferential direction.

  The support ring 13 is pressed from a ferromagnetic steel plate, for example, a ferritic stainless steel plate (JIS standard SUS430 or the like) or a rust-proof cold rolled steel plate (JIS standard SPCC or the like). It is formed by processing. As a result, it is possible to prevent the support ring 13 from rusting and to increase the magnetic output of the magnetic encoder 14 to ensure stable detection accuracy.

  The protective cover 10 attached to the inner side end of the outer member 2 is formed in an annular shape by press working from a nonmagnetic austenitic stainless steel plate (JIS standard SUS304, etc.). As shown in FIGS. 2A and 3, the protective cover 10 includes a cylindrical fitting portion 10a that is press-fitted into the inner periphery of the end portion of the outer member 2, and a reduced diameter portion 10b from the fitting portion 10a. A disc-shaped shielding portion 10c extending inward in the radial direction through a bottom portion 10b, and a bottom portion 10e for closing the inner end of the inner member 1 from the shielding portion 10c through a cylindrical portion 10d. The detection unit of the sensor (not shown) is brought close to or in contact with the shielding unit 10c of the protective cover 10, and the detection unit and the magnetic encoder 14 are arranged to face each other with a predetermined air gap (axial clearance) through the protective cover 10. Has been. Such a stepped shape increases the rigidity of the protective cover 10 and can suppress deformation due to flying stones, etc., and since the protective cover 10 is a non-magnetic material, it does not affect the flow path of magnetic flux and has excellent corrosion resistance. The durability can be improved over a period of time.

  In the present embodiment, the reduced diameter portion 10b of the protective cover 10 has a stepped shape, and the seal member 15 is fixed to the outer peripheral portion thereof. The seal member 15 is made of synthetic rubber such as nitrile rubber, and is integrally joined to the protective cover 10 by vulcanization adhesion, and includes a convex portion 15a and an annular portion 15b. The annular portion 15b is formed to be slightly smaller in diameter than the outer diameter of the fitting portion 10a, and the convex portion 15a is formed to be slightly larger in diameter than the outer diameter of the fitting portion 10a. The peripheral surface 2d is press-fitted through a predetermined scissors. Thereby, the airtightness of the fitting surface of the outer member 2 and the protective cover 10 can be improved over a long period of time.

  Here, as shown in FIG. 2B, the annular portion 15 b of the seal member 15 and the outer member 2 are in a state in which the fitting volume A of the convex portion 15 a of the seal member 15 is in contact with the press-fitting jig 16. The compression ratio of the convex portion 15a is regulated to 45% or less so as to be smaller than the volume B (A ≦ B) of the annular space formed between the inner peripheral surface 2d of the end portion (in FIG. Show). Thus, when the protective cover 10 is press-fitted, even if the convex portion 15a of the seal member 15 is compressed and raised, the annular portion 15b of the seal member 15 becomes an escape portion to allow it, and the end surface of the outer member 2 is allowed. It can prevent that it protrudes rather than 2c and is damaged.

  In addition, when the compression ratio of the convex part 15 of the sealing member 15 exceeds 45%, not only the press-fitting work becomes difficult, but also the elasticity of the material is remarkably lowered, and there is a possibility that airtightness may be lowered due to damage during press-fitting. Therefore, it is not preferable.

  Further, in the present embodiment, the inner end face 2c of the outer member 2 is formed so as to protrude by a step L1 to the inner side from the large end face 5b of the inner ring 5, and the shielding portion 10c of the protective cover 10 and the outer member are formed. The end face 2c of 2 and the detection face of the magnetic encoder 14 and the large end face 5b of the inner ring 5 are set to be substantially flush with each other. As a result, the protective cover 10 can be prevented from coming into contact with the inner ring 5. Further, if the detection surface of the magnetic encoder 14 and the large end surface 5b of the inner ring 5 are substantially flush with each other or set so as to slightly protrude toward the inner side from the large end surface 5b, the protective cover 10 is attached to the outer member 2. The support ring 13 can be accurately positioned and fixed with reference to the end surface 2c and the large end surface 5b of the inner ring 5 as a reference, air gap adjustment can be facilitated, and detection accuracy can be increased.

  Next, the processing method of the outer member 2 is demonstrated using FIG. In the present embodiment, the connecting portion 17 between the end inner peripheral surface 2d of the outer member 2 and the chamfered portion 2e is formed in an arc shape having a predetermined radius of curvature R. The end inner peripheral surface 2d and the chamfered portion 2e including at least the connecting portion 17 are simultaneously ground by a general grinding wheel 18. Thereby, the connection part 17 of 2 d of edge part internal peripheral surfaces and the chamfering part 2e is formed smoothly, the press fit property of the sealing member 15 improves, and it can prevent damage and the protrusion at the time of press fit.

  FIG. 4 is a modification of the protective cover 10 described above. The protective cover 19 is basically different from the above-described protective cover 10 only in the shape of the reduced diameter portion, and the same reference numerals are given to other identical portions, and the detailed description thereof is omitted.

  This protective cover 19 is formed into a circular shape by press working from a non-magnetic austenitic stainless steel plate (JIS standard SUS304, etc.) and is press-fitted into the inner periphery of the end of the outer member 2. A portion 10a, a disc-shaped shielding portion 10c extending radially inward from the fitting portion 10a via the reduced diameter portion 19a, and an inner side of the inner member 1 from the shielding portion 10c via the cylindrical portion 10d And a bottom portion 10e that closes the end portion. Such a stepped shape increases the rigidity as in the protective cover 10 described above, can suppress deformation due to flying stones, etc., and since the protective cover 19 is non-magnetic, it does not affect the flow path of magnetic flux, and also has corrosion resistance. And durability can be improved over a long period of time.

  Further, the reduced diameter portion 19a is formed in a tapered shape, and the seal member 20 is integrally joined to the outer peripheral portion by vulcanization adhesion. And the fitting volume of the convex part 20a of the seal member 20 is between the annular part 20b of the seal member 20 and the outer member (not shown) with the press-fitting jig (not shown) in contact. It is set to be smaller than the volume of the formed annular space. In the present embodiment, since the reduced diameter portion 19a of the protective cover 19 is formed in a tapered shape, the volume of the seal member 20 can be increased, and it is necessary to ensure airtightness without excessively increasing the compressibility of the convex portion 20a. The fitting shishiro can be set easily.

  The protective cover 21 shown in FIG. 6 has a cylindrical fitting portion 10a that is press-fitted into the inner peripheral surface 2d of the outer member 2 and a reduced diameter portion 10b that has a stepped shape from the fitting portion 10a. A disc-shaped shielding portion 21a extending inward in the radial direction and a bottom portion 10e for closing the inner side end portion of the inner member 1 from the shielding portion 10c through the cylindrical portion 10d are provided. Then, the detection unit 22a of the rotation speed sensor 22 is brought close to or in contact with the shielding unit 21a of the protective cover 21, and the detection unit 22a and the magnetic encoder 14 face each other with a predetermined air gap through the shielding unit 21a of the protective cover 21. Has been placed.

  Here, in the present embodiment, the plate thickness t1 of the shielding portion 21a of the protective cover 21 is formed to be thinner than the plate thickness t0 of the fitting portion 10a, the reduced diameter portion 10b, the cylindrical portion 10d, and the bottom portion 10e of other portions. ing. Thereby, the air gap between the detection unit 22a and the magnetic encoder 14 can be set small, and the detection accuracy can be further improved.

  Depending on the outer diameter and position of the rotational speed sensor 22, the seal member 15 may interfere with the seal member 15 before being brought close to the shielding portion 21 a of the protective cover 21. It is set so that it does not protrude to the inner side from the outer surface of the shielding part 21a in a single state before being fitted to the member 2. Thereby, in order to avoid interference with the seal member 15, it is not necessary to move the rotation speed sensor 22 away from the magnetic encoder 14 more than necessary, the air gap can be set to a minimum, and the detection accuracy can be further improved. . Here, at least the protective cover 21 is set so as not to protrude to the inner side from the outer surface of the shielding portion 21a in a single state before being fitted to the outer member 2, but the protective cover is It is preferable that the outer member is set so as not to protrude to the inner side from the outer surface of the shielding portion 21a in a state of being fitted and fixed to the outer member (that is, in use).

  The embodiment of the present invention has been described above, but the present invention is not limited to such an embodiment, and is merely an example, and various modifications can be made without departing from the scope of the present invention. Of course, the scope of the present invention is indicated by the description of the scope of claims, and further, the equivalent meanings described in the scope of claims and all modifications within the scope of the scope of the present invention are included. Including.

  The wheel bearing device according to the present invention can be applied to the wheel bearing device on the driven wheel side of the first to third generation structure of the inner ring rotation type.

DESCRIPTION OF SYMBOLS 1 Inner member 2 Outer member 2a Outer rolling surface 2b Car body mounting flange 2c End side 2d of outer member Inner side end surface 2e Outer member end inner peripheral surface 2e Chamfer 3 Rolling element 4 Hub wheel 4a, 5a Inner rolling Surface 4b Small diameter step portion 5 Inner ring 5b Large end surface 6 Wheel mounting flange 6a Hub bolt 6b Inner side base 7 Clamping portion 8 Cage 9 Outer side seals 10, 19, 21 Protective cover 10a Fitting portions 10b, 19a Reduced diameter portion 10c, 21a Shielding part 10d, 13a Cylindrical part 10e Bottom 11 Core metal 12 Sealing member 12a, 12b Side lip 12c Grease lip 13 Support ring 13b Standing plate part 14 Magnetic encoder 15, 20 Sealing member 15a, 20a Protruding part 15b, 20b Ring Portion 17 Joint 18 Grinding wheel 50 Outer member 50a Outer rolling surface 50b Car body mounting flange 51 Inner member 52 Bo 53 Hub wheel 53a, 54a Inner rolling surface 53b Small diameter step part 53c Caulking part 54 Inner ring 55 Wheel mounting flange 55a Base part 56 Seal ring 57 Encoder 58 Support ring 59 Encoder main body 60 Cover 61 Closing plate part 62 Fitting part 63 Sensor 64 Detector 65 Knuckle 66 Screw L1 Step t0 between outer member and inner ring Protective cover thickness t1 Protective cover shield thickness

Claims (9)

An outer member in which a double row outer rolling surface is integrally formed on the inner periphery;
From a hub wheel integrally having a wheel mounting flange for mounting a wheel at one end and having a small-diameter step portion extending in the axial direction on the outer periphery, and at least one inner ring press-fitted into the small-diameter step portion of the hub ring An inner member in which a double row inner rolling surface facing the outer rolling surface of the double row is formed on the outer periphery,
A double row rolling element housed movably between the rolling surfaces of the inner member and the outer member;
A magnetic encoder fitted on the inner ring,
A seal is attached to the outer end of the outer member,
In the wheel bearing device in which a protective cover is attached to an inner side end of the outer member, and an opening of an annular space formed by the outer member and the inner member is sealed,
The protective cover is formed in a cup shape from a non-magnetic steel plate, and has a cylindrical fitting portion that is press-fitted into the inner peripheral surface of the end portion of the outer member, and a diameter from the fitting portion through a reduced diameter portion. And a disc-shaped shielding portion that extends inward in the direction, and the rotational speed sensor is close to or abuts on the side surface on the inner side,
A seal member is integrally joined to the outer peripheral portion of the reduced diameter portion, and is press-fitted to the inner peripheral surface of the end portion of the outer member via a predetermined shimiro,
An end surface on the inner side of the outer member is formed so as to protrude to the inner side from the large end surface of the inner ring, and a gap is provided between the large end surface of the inner ring and the shielding portion. Bearing device.   The wheel bearing device according to claim 1, wherein the seal member includes a convex portion formed to have a diameter slightly larger than the outer diameter of the fitting portion of the protective cover.   The wheel bearing device according to claim 1, wherein the reduced diameter portion is formed in a tapered shape.   The said sealing member is set so that it may not protrude to the inner side from the outer surface of the said shielding part at least in the single-piece | unit state before fitting the said protective cover to the said outward member. Wheel bearing device.   From the volume of the annular space formed between the annular portion of the seal member and the inner peripheral surface of the end portion of the outer member, with the fitting volume of the convex portion of the seal member being in contact with the press-fitting jig. The wheel bearing device according to claim 2, which is set to be smaller.   2. The wheel bearing device according to claim 1, wherein the detection surface of the magnetic encoder and the large end surface of the inner ring are set to be substantially flush with each other or slightly protrude toward the inner side of the large end surface.   The wheel bearing device according to claim 1, wherein a connecting portion between the inner peripheral surface of the end portion of the outer member and the chamfered portion is formed in an arc shape having a predetermined curvature radius.   The wheel bearing device according to claim 7, wherein an inner peripheral surface of the end portion of the outer member and a chamfered portion including at least the connecting portion are simultaneously ground by a general grinding wheel.   The wheel bearing device according to claim 1, wherein a plate thickness of the shielding portion of the protective cover is formed to be thinner than plate thicknesses of other portions.

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